Case-stacking apparatus



April 29,, 1958 J. J. BARSKI CASE-STACKING APPARATUS Filed May 29, 1956 2 Sheets-Sheet INVEN7UR: $44430,

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A A BY A N 29, 1958 J. J. BARSKI CASE-STACKING APPARATUS 2 Sheets-$heet 2 Filed May 29, 1956 INVENTOR- sy dwa /fii ATT NEYS.

United States Patent CASE-STACKING APPARATUS Julius J. Barski, Chicago,

Paulson Company, nois 111., assignor to The Lathrop- Chicago, 111., a corporation of Illi- This invention relates to an improved apparatus for stacking cases, cartons, and the like. The present application is a continuation-in-part of my copending applicationSerial No. 581,925, filed May 1, 1956.

In the aforementioned copending application, I have disclosed an apparatus for receiving cases in single file and for arranging the cases one upon the other to form a stack which may then be carried off on an exit conveyor. One of the main objects of the present invention is to provide an improvement for such an apparatus, whereby the machine is capable of receiving and stacking cases of different size. More specifically, an object of this invention is to provide a case stacker equipped with means for centering and guiding cases as they are being stacked, the means automatically adjusting itself to receive series of cases of different widths. Another object is to provide automatically adjustable guide means cooperable with the carriage structure of the stacker for receiving, stacking, and centering cases of different width. A further object is to provide movable guide means cooperating with the stacker mechanism for arranging and stacking a series of cases arriving in single file, the guide means being automatically reset to receive and center another series of cases of different size after the preceding series of cases has been stacked.

Other objects will appear from the specification and drawings, in which:

Fig. 1 is a broken end view in elevation showing a stacker apparatus equipped with the adjustable guide means of the present invention; Fig. 2 is a horizontal section taken along line 2-2 of Fig. 1-; Fig. 3 is a broken vertical section taken along line 3-3 of Fig. 1; and Fig. 4 is a broken perspective view of the self-adjusting guide structure.

In the illustrations given, A designates a vertical carriage frame and B designates a vertically movable carriage. In the operation of the structure I provide means for raising and lowering the carriage so as to carry cases as they are stacked one upon the other to a lower position where they are discharged from the stacker. C designates a rocker mechanism providing a rotatable support for the cases, the support being effective for lowering the cases one upon the other for the stacking operation. The letter D generally designates the guide mechanism which is the subject matter of the present invention. Guide mechanism D receives and directs cases upon the rocker mechanism for the stacking of those cases upon the carn'age, as will be described shortly.

The frame A comprises side standards and 11, there being two standards 10 and two standards 11 each spaced apart to form a frame which is substantially square in cross-section. The frame also includes the top member 12, side members 13, and horizontal frame members 14, 15, and 16. These members may be welded or otherwise secured to each other to provide a rigid frame structure.

The carriage B comprises a pair of members 17 having vertical arms 18 and inwardly extending horizontal arms foremost case 19. The upwardly extending arms 18 are equipped with rollers 20 carried within the vertical channels of frame standards 10 and 11. inwardly extending arms 19 are provided with case-support members 21 at the inner ends thereof for supporting and lowering cases during a stacking operation.

Any suitable means for conveying the boxes X forwardly to the stacking machine may be employed. In the illustration given, I provide a pair of chain conveyors 22 and these pass over sprocket wheels 23 carried by shaft 24, the shaft being rotated by a motor-driven chain 25 which engages spocket 26. As the cases X are advanced, they pass between guide walls 27 and 28 of adjustable guide mechanism D and leave the conveyors 22, being moved forwardly by the tilted roller structure C. The roller structure C will now be described.

Brackets 29 are carried by the side rails 10 and 11 and in each of the brackets is mounted a rotatable shaft 30. The rotatable shaft carries supports 31 in which are mounted spindles for rotatably supporting spools 32. The spindles supporting the spools are equipped with sprockets which engage continuous motor-driven chains 33. With this structure the several spools 32 may be rotated for advancing cases thereon, while at the same time the spools may be simultaneously rotated either downwardly or upwardly upon their power-driven rock shafts so. By this means the cases X may be advanced rapidly by the rotating spools 32 and then dropped from the spools when the same are swung downwardly by the rotation of shafts 30.

Any suitable means may be provided for raising and lowering the carriage B. In the illustration given, 1 provide hydraulic means in the form of a pressure fluid cylinder 34 which is equipped with a piston 35 carrying at its upper end a freely rotatable sprocket wheel 36 engaging a chain 37. One end of the chain is anchored to the lower portion of the stacker frame, while the other end of the chain is connected by bracket 38 to the movable carriage B. By reason of the mechanical advantage in this arrangement, carriage B will travel twice the vertical distance of piston 35 as that piston moves upwardly or downwardly within piston cylinder 34. To provide uniform support for the vertically movable carriage, I employ an equalizer chain 39. The equalizer chain is connected to opposite sides of the carriage by means of brackets 40 and 41 and is entrained about a lower idler sprocket (not shown) rotatably mounted upon the stacker frame, and a pair of upper idler sprockets 42 and 43.

rotatably mounted upon the top frame member 12. Thus, upon the forcing of fluid into cylinder 34, it is possible to raise the piston 35 or by withdrawing liquid from the cylinder 34, to lower piston 35 and thus raise or lower the carriage B.

It will be understood that any suitable pumping means for supplying fluid to the power cylinder or to either end thereof may be employed to bring about the raising and lowering of carriage B.

Operation of the carriage is controlled by means of i an electric lamp 44 which directs a light beam 45 towards an electric cell 46. When this beam is interrupted by a case supported by the movable carriage, hydraulic piston 35 is actuated and lowers the carriage. As the carton passes below the light beam, the circuit is again completed and the carriage is stopped to receive the next case of the stack. As pointed out above, the foremost case of an incoming series of cases is supported by roller supports 32 and is dropped upon the carriage, or upon roller supports pivot the cases carried thereby, when the downwardly and outwardly. T he tilting operation of the roller supports is controlled by a switch 47 equipped with a switch arm 48. When the switch Patented Apr. 29, 1958v arm is engaged by the and is moved forwardly, Powendriven shafts rotate and pivot the roller supports downwardly and outwardly to release that case. The cases are kept separated during the feeding movement of the roller supports by stop members 49 which extend inwardly to limit forward movement of the following cases as the foremost case is being released by the roller supports.

When the vertically movable carriage B has reached a lower position and supports a selected number of stacked cases, the stack is then removed from the carriage and piston is driven upwardly to return the carriage to its original position. Any suitable conveyor means may be employed for removing the stacked cases from the carriage.

It is believed that the above description sets forth the structure and operation of the stacker in sufiicient detail to illustrate an operative environment for the adjustable guide structure of the present invention. However, if a more detailed description of the stacker apparatus is desired, reference may be had to my copending application Serial No. 581,925;

Referring now to Figs. 2, 3, and 4, it will be seen that the adjustable guide structure includes a pair of vertical side plates 27 and 23 which are movably suspended from transverse frame members 15 and 16. As illustrated most clearly in Fig. 4, the transverse frames have generally C-shaped cross-sections defining longitudinal channels or tracks. A pair of T-shaped support members 50 suspend each guide plate from the channel frames and are equipped with rollers 51 at the ends of their horizontal arms which ride along the channels of frames 15 and 16. The vertical portions of the T-shaped supports are welded or otherwise secured to the outer surface of the horizontally elongated guide plates 27 and 28.

Preferably, the upper horizontal edge of each guide plate is provided with an outwardly projecting flange 52 which may be either formed integrally with the plates or secured thereto by any suitable means. Flanges 52 support the latching and synchronizing means which will now be described.

As noted above, the parallel guide plates are suspended from channel frames 15 and 16 for horizontal movement in opposite directions. As illustrated in Fig. 2, these opposing guide plates are in parallel alignment with feed conveyors 22. So that the opposing plates 27 and 23 will be at all times at an equal distance from a longitudinal midline passing between conveyors 22, I provide a pair of linking arms 5'3 which synchronize movement of the plates and equalize the distance of their outward or inward movement. Adjacent ends of links 53 are pivotally connected by a connector 54 which rides along the longitudinal slot 55 of a centrally disposed link support member 56 mounted upon transverse frame 15. The opposite or remote ends of links 53 are pivotally secured to the opposing guide plates by pins 5'7. If desired, sleeves 58 may be employed to maintain links 53 in substantially horizontal positions.

The latching or restraining means comprises an elongated lever arm 59 having one of its ends pivotally con- .nected by pin 60 to guide plate 28 and having its other end portion notched for frictionally engaging an upstanding post 61 carried by plate 27. The guide plate restraining lever 59 is provided intermediate its ends with an upstanding member 62 which is apertured to receive a threaded spring connecting rod 63. The rod 63 has one end adjustably secured to the upstanding member by means of opposing nuts 64 and has a transverse opening adjacent its other end to receive one end of tension spring 65. The other end of the tension spring is hooked upon an angled connector 66 which is welded or otherwise attached to transverse channel frame 15. Spring therefore urges the notched portion of the pivotal restraining lever 59 into engagement with post 61.

As shown best in Figs. 1 and 4, a guide platere'turn lever 67 is pivotally mounted intermediate its upper and lower ends upon a bracket 68 securely fastened to frame member 69 above the opposing guide plates. Lever 67 is positioned and arranged for pivotal movement along a plane normal to the line of movement of cases carried by conveyors 22. The lower end portion of the lever is engageable with the outwardly extending flange of guide plate 28 and the upper end portion of that lever is engageable with a lug 70 which is carried by chain 39 and which moves along substantially the same plane defined by the pivotal movement of the lever. Preferably, the lug 70 is provided with upper and lower portions 71 and 72 respectively, these portions being connected together by a one-way hinge. As the chain 39 moves in the direction indicated by the arrow in Fig. 4, the lower portion 72 of the lug engages the upper portion of lever 67 and pivots the lever in a counter-clockwise direction. However, when the lug approaches the lever from the opposite direction, lower portion 72 will pivot upwardly upon its one-way hinge and ride over the upper end of the lever.

As explained above, the ends of chain 39 are connected to opposite sides of the carriage B so that this chain will travel over sprockets 42 and 43 in response to vert1cal movement of the carriage. Referring to Fig. 4, the equalizer chain 39 will move towards the left when the carriage moves upwardly, and will travel towards the right when the carriage moves downwardly during a stacking operation. Therefore, it is evident that lever 67 is pivoted to urge the guide plates 27 and 28 towards each other only when the carriage is returning to its elevated position.

As lever 67 is rotated in a counter-clockwise direction (Fig. 4), the lower end of that lever engages flanged guide plate 28 and drives the plate inwardly along channel frames 15 and 16. At the same time, the link 53 extending between plate 23 and the slotted member 56 drives the connecting stud 54 rearwardly along slot 55, thereby urging plate 27 inwardly a distance corresponding with the distance of inward movement of plate 28. finally, when the carriage has reached its highest positron, stops 49 (Fig. 1) are lifted and feed conveyors 22 drive the first case of .a series against the diverging deflector portions 73 of the guide plates. These deflector portions serve the two-fold function of centering the oncoming case and providing an abutment surface which permits the forwardly driven case to separate the plates a distance suflicient to receive the case therebetween. It Wlll be noted that notched restraining lever 59 does not prevent the separation of the guide plates by the oncoming case X, but only restrains movement of the plates by the cases after the plates have been separated a sufficient distance to accommodate them.

When the foremost case has been received between the guide plates and has been centered by those plates upon roller supports 32, the forward end of the case engages switch arm 48 and the roller supports pivot downwardly and outwardly to drop the centered case upon carriage B. The carriage then moves downwardly until light beam 45 is no longer interrupted. The next case, which in the meantime has been centered by guide plates 27 and 28, is then deposited upon the first case supported by the movable carriage. This process continues until all the cases of the series have been sequentially stacked upon the carriagethat is, until the carriage B has received its full complement of stacked cases. The stack is then removed from the carriage and the carriage moves upwardly to receive the first case of the next series. As the carriage travels upwardly, lug 70 contacts the upper end of guide plate return lever 67 and this lever urges the plates inwardly in the manner already described.

Preferably, the cases X are arranged upon the feed,

conveyors 22 so that all the cases of a single series are of the same size. The adjustable guide means will center each of the cases and, in cooperation with the vertically movable carriage B, will produce stacks of neatly ar-.

ranged cases. It will be understood, however, that the cases of each series may be of different size, and that even if the cases are intermixed the adjustable guide means D will operate to properly center and arrange the cases. For example, if the first case of a series is narrower than the second case, each of the guide plates will move outwardly a corresponding distance to accommodate the larger case and to center that case directly above the smaller first case.

While I have disclosed an embodiment of the present invention in considerable detail for purposes of illustration, it will be understood by those skilled in the art that many of these details may be varied without departing from the spirit and scope of this invention.

I claim:

1. In an apparatus for receiving successive series of cases in single file and for sequentially arranging the cases of each series to form a stack, an adjustable guide structure comprising a pair of opposing plates movable towards and away from each other for receiving and centering each of the cases therebetween, means for synchronizing opposing movement of said plates, a latch structure for restraining inward movement of said opposing plates while the cartons of each of the series are being stacked, and means for urging said plates towards each other before the first case of each series is received therebetween.

2. The structure of claim 1 in which said plates have diverging deflecting portions for directing oncoming cases between said plates and for separating said plates a distance equal to the width of said cases in response to engagement therewith and have straight parallel portions for holding the cases in centered condition during stacking.

3. The structure of claim 1 in which the means for urging said plates towards each other comprises a guide plate return lever having one end thereof engageable with one of said plates, and means for pivoting said lever to urge said plates towards each other before the first case of each of the successive series is received therebetween.

4. In a stacking apparatus having a vertical frame, a vertically movable carriage mounted therein for lowering cases through predetermined distances, a tiltable case support over said carriage for releasing cases thereon and conveyor means for feeding cases upon said support, an adjustable guide structure above said support comprising a pair of opposing plates movable in opposite directions for receiving cases of diiferent size therebetween and for centering said cases upon said support above said carriage, means for synchronizing opposing movement of said plates, and means for urging said plates towards each other upon the upward movement of said carriage following a stacking operation.

5. The structure of claim 4 in which the means for 55 urging said plates towards each other comprises a lever pivotally mounted upon said frame and having one end engageable with one of said plates, a lug adapted to engage the opposite end of said lever for pivoting the same and driving said plates towards each other, and movable means attached to said carriage and supporting said lug for urging said lug against said lever when said carriage moves upwardly.

6. The structure of claim 4 in which said synchronizing means comprises a pair of arms having a pair of adjacent ends pivotally connected to each other and having their opposite ends pivotally mounted upon said opposing plates, and means for allowing movement of the connected adjacent ends of said arms only along a line perpendicular to the direction of movement of said opposing plates.

7. The structure of claim 4 in which adjustable restraining means are provided for restraining movement of said opposing plates.

8. In a case-stacking apparatus, a vertical frame, a conveyor adapted to deliver cases successively to an upper portion of said frame, a vertically movable carriage mounted in said frame for lowering cases in a stack, releasable case support means for receiving cases from said conveyor and for successively stacking said cases upon the carriage, and adjustable guide means for directing cases from said conveyor upon said support means and for arranging said cases thereon, said guide means comprising a pair of opposing plates movable towards and away from each other for directing and centering cases of different size upon said support means, means for synchronizing opposing movement of said plates, and means for urging said plates towards each other as said carriage moves upwardly.

9. The structure of claim 8 in which said synchronizing means comprises a piar of arms of substantially equal length having a pair of adjacent ends pivotally connected to each other and having their opposite ends pivotally mounted upon said opposing plates, and means for allowing movement of the adjacent ends of said arms only along a line perpendicular to the direction of movement of said opposing plates.

10. The structure of claim 8 in which said plates have diverging portions adjacent said conveyor for directing oncoming cases between said plates and for separating said plates a distance equal to the width of said cases in response to engagement therewith.

References Cited in the file of this patent UNITED STATES PATENTS 1,474,448 Scott Nov. 20, 1923 2,005,906 Pierce June 25, 1935 2,781,119 Talbot et a1. Feb. 12, 1957 

